Lyrics:

I got a letter just the other day
She sent a picture, but she didn't sign her name
She wore high heels and a little black lace
I knew her body, but I couldn't see her face

She didn't leave a number, not an address or a clue
But something in that photograph reminded me of you

Baby, let's put the X in sex
Love's like a muscle and you make me wanna flex
Baby, let's put the X in sex
Keep it undercover, baby let me be your private eye

I got a call in the middle of the night
Heavy breathin' never sounded quite so nice
She said 'Ooh yeah, I wish that I was there'
I asked who was calling, but she wasn't playing fair

Sometimes you gotta suffer for the pleasure that you seek
You're beggin' for an eyeful but you only get a peek

Baby, let's put the X in sex
Love's like a muscle and you make me wanna flex
Baby, let's put the X in sex
Keep it undercover, baby let me be your private eye

Oh yeah (yeah)

I heard somebody knockin' so I opened up the door
She wore a hat, shades and a trench coat, wasn't wearin' that much more
She said she knew my secrets but I didn't have a clue
Then I saw those black lace panties and I knew that it was you

Baby, let's put the X in sex
Love's like a muscle and you make me wanna flex
Baby, let's put the X in sex
Keep it undercover, baby let me be your private eye

Let's put the X in sex
Love's like a muscle and you make me wanna flex
Baby, let's put the X in sex
Keep it undercover, baby let me be your private eye

Let's put the X in sex
Love's like a muscle and you make me wanna flex
Baby, let's put the X in sex
Keep it undercover, baby let me be your private eye

Let's put the X in sex